This application claims priority to China Patent Application No. 201410092251.7 filed on Mar. 13, 2014 entitled, CIRCUIT AND METHOD FOR REDUCING INDUCTOR MAGNETIC-CORE LOSS, all of the disclosures of which are incorporated herein by reference in their entirety.
1. Field of Invention
Embodiments of the present disclosure relate to electronic technology, and more particularly to a circuit and method for reducing inductor magnetic-core loss.
2. Discussion of the Related Art
As shown in FIG. 1, when the light-emitting diode (LED) is driven, generally, the lights are adjusted by changing the duty-cycle ratio of the low frequency, i.e., 100-240 HZ, pulse width modulation (PWM) signals. The operation frequency of the switch transistor (Q1) remains the same regardless whether the duty-cycle ratio of the PWM signals has been adjusted. Thus, the current of the inductor (L1) also remains the same, which results in the inductor magnetic-core loss due to an increased temperature for the conditions such as charging the pull-down regulator, performing the full-power testing, performing the temperature testing at the inductor ends, and so on. When the temperature increases, the inductor magnetic-core loss accumulates, and thus the inductor may be burnt.